Method of making producer-gas.



. y 11-1'. SMITH. MB'rHon oF MAKING PBOD'UGBB GAS. APILIOATION FILED DEO. 9. 1909.

1,027,290. 'l Patented My'21,19`12.

UNITED sTATEs PATENT OFFICE,

HARRY F. SMITH, OF LEXINGTON, OHIO.

METHOD 01E MAKING PRODUCER-GAS.

Specification of Letters Patent.

' Patented May 21, 1912.

Application led December 9, 1909. Serial No. 532,273.

' ject is to suspend the fine fuel in the combustion chamber and during combustion by means of an upwardly directed air current having varying velocities at'different' parts of the producer, whereby the fuel particles Iwill be separated, causing the large particles to be at the bottom and the lightest to be at the top of the producer, but the entire fuel bed supported upon `the upwardly directed air current.

Great difficulty has been experienced in producing gas from fine fuel. In many types of producers the coal and air are fed into the producer together, the coal being reduced to a very ne powderso as to be carried in suspension by the ingoing current of air. In producers of this character, where pulverized fuel is used, there must be a constant supply of fuel and air, 'as there is no surplus fuel contained within the pro ducer proper, and the slightest momentary interruption of the fuel supply causes an absolute stoppage of gas production until the fuel supply is restablished. On account of this difficulty for maintaining 'con-v tinuous .conditions -of supplying the fuel and air, it has been found advisable tosupplement producers of this character with a zone of solid fuel, through which the highly heated products of combustion are passed, in order to establish a more stable'gas quality, and at the same time to more perfectly reduce the products of combustion to conbustible gases. When an attempt is made to use finely divided fuels, that is to say, slack or culm, in producers of the ordinary .type maintaining a solid fuelbed, greatdificulty is' experienced on account of the fact that it is difficult, if not impossible to main- 4tain a sufficiently deep fuel bed to complete the gas making reaction without at the same time creatin difficulty from channeling and an uneven distribution of the blast.

In the accompanying drawings is dis# closed avertical sectional View of an apparatus which may be used in carrying out my invention.

A represents the shell of the producer and B is the refractory lining. The internal .contour of the producer is formed to produce a uniform decrease inair velocity from the lowest to the highest position, which in this instance gives the interior of the producer a shape similar to that of an inverted cone. The bottomof the producer is pro-- vided with a small or constricted opening forming a throat C through which the air isdischarged into the producer. Below the v producer is the ash pit or cinder box 1. Connected to the boX is a pipe 2, which pipe is connected to an air blower M; a line c shaft L is adapted to .receive power from any suitable source, and mounted upon theshaftis a pulley 3, from which an endless belt 4 passes. A pulley 5 on the air blower M has the endless belt passing therearound, and upon the rotation of the line shaft L, the belt 4; will cause thc air blower to be operated for supplying the producer with a current of air, the supply of air being governed by the speed ofv the shaft L.

A hopper E is mounted preferably at the top of the producer, through which the line fuel is discharged into the producer.

feeder 6 is mounted in the hopper, causing a discharge of fuel from the hopper into the producer, and connected to the feeder is a gear wheel 7. A variable speed shaft N is provided with a pinion 8 which is adapted to mesh with the gear wheel 7. A friction wheel 9 is slidably mounted upon the shaft N and is adapted to engage the surfaceof the friction pulley 3; a lever 10 engages the friction disk 9 and is adapted to shift the friction disk along the surface of the fric'- tion pulley 3 for regulating the speed of the shaft N, .and governs the supply of' fuell from the hopper to the producer. An outlet D is formed in the Wall of the producer through which the gas is dischargedfrom the producer. A grate P is slidably mounted in the Wall of t-he producer and is adapted to be received in the throat C for starting or kindlin the fire. .After the fire has been started t e grate is Withdrawn from the throat into the lining of the producer and the fire is suspended 1n the producer by the air blast.

The fuel used in producing the gas is very fine, including practically no fuel that will not pass through a screen approximately one-quarter of an inch in mesh. Fuel which is artificially pulverized could be used although I find that the screenings commercially known as slack and consisting of particles from the finest dust to the largest desirable size as specified, can be very satisfactorily and economically used.

The apparatus is started by moving the grate into the throatvC of the producer,

whereupon the fire is kindled, and as soon as the fire begins to burn brightly, the shaft L is caused to rotate, whereby motion is transmitted to the blower M, causing a supply of air to be dischar ed into the producer through the throat which will support the fuel bed. Upon the rotation of the shaft L and the operation of the air blower M, motion is also transmittedto the shaft N, causing the feeder 6 to be operated for discharging a supply of fuel to the producer. The coal or fuel is immediately ignited from the fire belowAvhich is supported or suspended by the air blast, and combustion begins to take place in theregular way. As soon as the supply ofv fuel from the hopper E is well established and the combustion within the producer regulated, the grate P is withdrawn, leaving the throat C unobstructed, upon which the' apparatus can be brought up immediately to its full working4 capacity.

The supply of air which is discharged into the producer will vary in velocity as it passes upwardly toward the top of the producer. The greater velocity will be at the bottom or throat of the producer, and the fuel, as it is discharged through the hopper, will be separated as it comes into contact with the air blast, allowing the larger particles to pass down into the producer toward the throat C, where it will be supported by the air blast or current, and the different sizes of fuel will be accordingly supported by the air blast, the finest of the fuel being supported at the top. For example, I have indicated in the drawings the large size fuel at K, the next at H, the next at G, and the fine fuel at F. The velocity of the air above the point F being sufiiciently low to prevent the fuel from being carried into the outlet D, and the velocity of the air at the throat C is sufficiently high to preventmthe largest pieces fired from passing through to the ash pit. The throat C is made sufficiently small, so that for any normal operating condition of the producer the air velo/city through the throat will be great enough to absolutely prevent any of the fuel from falling through the throat, and the fuel is actually supported in its entirety on the ascending a1r current.-

The separation of the fuel as above outlined, having the larger particles of the fuel at the throat of the producer and the finer particles lat the top, the larger particles will be rst subjected to the action of the air blast, and are hence wholly consumed in the primary combustion. The hot products of combustion inpassing upward into the producer, encounter successively increasing areas and surfaces of finely divided fuel offering a most favorable condition for the secondary or reduction of reaction required for the formation of producer gas. Owing to the fact that the particles of fuel are supported by the air current, there is no ossibility of channeling as in the case o producers maintaining a solid fuel bed, but this V arrangement enables definite zones of primary and secondary combustion to be maintained in the producer for the complete production of gas in a way that is not possible with other producers firing pulverized fuel. There is further an appreciable quantity of fuel in the machine, and a momentary interruption will not result in an instantaneous interruption of gas making, since it would be necessary to consume entirely the mass of fuel suspended in the producer before gas making would cease.

Of course, the supply of fuel and air pressurey must/be regulated so that there will not be a greater supply of air than coal, which would allow the air to pass on through .the gas outlet D without being consumed.

On the other hand, if the fuel supply is greater than the air supply the fuel will continue to accumulate within the producer until the air current is no longer able tosustainit, when a part of the fuel will be carried out with the gas through the gas outlet D, and some ofthe fuel will pass through the throat C of the producer. The fuel, as it descends into the hopper will meet the ascending stream of air having at different parts of the producer various velocities which will cause the fuel to separate under the influence of the air current, and each particular particle of fuel will remain in that portion of the producer where the gas velocity is sufficiently great to support its weight.

The temperature within the producer is maintained sufficiently high to give either partial or total fusion of theashes. If the ashes are partially fused, small clinkers or cinders will be formed which will be carried in suspension throughout the fuel bed I on the supporting air current, but as they increase in size they will gradually descend` and pass through the throat C to the ash pit, due to the fact that` the will become toO heavy to be supported by t e air current. If fusion of the ashes occurs, the fused slag will trickle down the lining of the producer and can be caught and tapped out into av distance from the throat to the outlet was approximately one hundred inches. The gas producedl did not differ materially in composition from that of the ordinary -producer gas from the same fuel. The gas burned freely and Was of excellent quality, except for the ad- .mixture of considerable lamp-black. The

amount of lamp-black produced depended on the temperature at which the furnace was operated and did not oii'er any practical diiiiculty either in the operation of the plant or the use of the gas. The blast pressure employed in this particular instance amounted to about twenty-four inches of water, or in other words, about one pound per square inch and the fuel was intermixed including from the finest dust to particles which Will pass through an approximately one-quarter inch mesh. The ash was found to fuse into a'slag when the fusing point of the ash was sufficiently low, in whlch case it could be tapped out through the slag twyer, as shown at 12. There was considerable tendency for slag to collect on the sides of the lining, from which it drained downward as it accumulated. When the normal fusibilit-y of this ash was not great enough to permitv of its being handled in this manner, the semi-liquid slag was allowed to accumulate on the side of the lining until'it began to obstruct the producer, when it was barredv loose and discharged through the throat C into the ash-pit. There was no tendency to complete oxidization, except where the fuel supply was very greatly reduced, when, of course, there was passage of unburned air through the fire, and a consequent heavy production of carbonio acid and other noncombustible gases. No difficulty was encountered in maintaining partial combustion under a blast rate sufficient to support the fuel.V

I do not wish to` be limited to the means for feeding coaland supplying air to the producer, as any suitable means may be employed -for supplying the air and fuel in practically continuous amounts.

. coarser particles being I am' aware that producers have beenpatented for theguse of pulverized coal, but in this the` fuelis not suspended in the air blast, but is simply carried into the pro- 1 ducer along with the" air and burned instantly2 the fair blast being generally directed 1n a horizontal, instead of a vertical,

direction. In my invention I provide an upwardly directed air current having varying velocitiesat different parts of the producer, whereby the fuel particles are se arated one from the other and the entire fiiel bed is supported on the air current, the subjected to the most vigorous air blast an the prlmary combustion and the separated particles, with very large surface in proportion to their mass, being made use of to secure the secondary or reduction reaction.

Having fully described my invention, what` I desire to secure by Letters Patent 1s:-'

1.V A method for producing producer gas,

consisting in supplying fuel of varying sizes tothe producer and supplying air to the producer for supporting the fuel.

2. A method for producing producer gas, consisting in supplyin air to the producer, and supplying fuel ofg varying sizes to the forming the basis for producer 1n an opposite direction to the supply of air, and the fuel being' suspended by the air current.

3. A method for producing producer gas, consisting in continuously supplying air to the producer, andcontinuously delivering fuel of varyigsizes to the producer which fuel is suspended by the air current.`

4. A method for producing producer gas,`

5. A method for producing producer gas,

consisting in supplying an .upwardly directed air current having varying velocities at different parts of the producer, and supplying tine -fuel to the producer which is separated and suspended byy the air current, causing the larger particles to be at the bottom, and the smaller at the top.

- 6. A method for producing producer gas, consisting'in supplying fuel to the producer,

and supplying an air blast for supporting the fuel 1n suspension and separating the fuel whereby ythe proper action may bey obtained on the fine fuel.

v7. A method for producing producer gas,

consisting in supplying fuel to the producer, and supplyingv `an upwardly directed air blast for supporting the fuel in suspension and separating the fuel-for obtaining the proper action onthe iine fuel. v

8. A method for producing producer gas, consisting in supplying fuel to the producer,

` und supplying mr to the producer for suspending and causing the fuel to be in motion.

fuel and causingv the fuel to'be separated and 10 ,f

in motion. A

In testimony whereof I aix my signature,

in the presence of two Witnesses.

HARRY F. SMITH. 

